let a:String='kevin';
let b:Number=123;
let d:Boolean=false;
let e:String[]=['123','321'];
let f:Number[]=[123,321];
let g:Boolean[]=[true,false];
let h:[string,number,Boolean]=['123',123,false]
let i:enum=Color.a;
let j:object={}
let k:

//联合类型
let l:string|number=123;